Parallel Feeders

[mull982]

Hello

I am new to the whole parallel feeders practice and was wondering how the feeders are terminated at their ends. I understand that the total ampacity of the load is split among the sets of parallel feeders and run, but what about when the sets of feedrs get to a load such as a motor? How are three sets of parallel feeders then connected to a motor? Do you need special parallel adapting hardware. I also am wondering the same thing about how they are terminated at an MCC. Can anyone shed some light on this?

Thanks

Mull982

 

[hockeyoligist2]

duplicate!@! 1 post is all you need be patient the guru's will be here soon

 

[charlie b]

I am going to keep this one open, and close the other one. This is a new thread, and the other post is a change of subject in someone else's thread. The other one had one comment, so I will move that comment here.

 

[charlie b]

Here is the one reply from the other thread. Please continue the discussion of this topic here.

Larger circuit breakers, panels, switchgear, and disconnects usually have means to land parallel feeders. For example, a Square D L type breaker is rated up to 600A, and it has provisions for landing 1 or 2 sets from 4/0 to 500KCM.

I've never fed a motor with parallel sets, so I'm not sure how you would terminate them. If you are trying to overcome voltage drop incurred on a long run, I would probably just set a disconnect at the motor, and then run a single set of wire to the motor.

 

[Smart $]

Hello

I am new to the whole parallel feeders practice and was wondering how the feeders are terminated at their ends. I understand that the total ampacity of the load is split among the sets of parallel feeders and run, but what about when the sets of feedrs get to a load such as a motor? How are three sets of parallel feeders then connected to a motor? Do you need special parallel adapting hardware. I also am wondering the same thing about how they are terminated at an MCC. Can anyone shed some light on this?

Thanks

Mull982

Parallel terminations are usually one of two methods: 1) mechanical or 2) compression. On gear having busbars, typically compression terminals are used (fci-burndy illustration). Where space is limited, typically multiconductor mechanical "lugs" are used. For many of the large-frame breakers and switchgear the "lugs" are ordered to your specific needs, but can usually be refitted easily on-site should circumstances change (Of course you will have to have the proper lugs on hand to change 'em out ).

I've only seen parallel feeders to a motor a couple timesin the recent past and both of times it was only two sets of feeders. From those experiences, I'd hate to be involved with a project that had more than two Fortunately in both of those instances, the motors had terminal blocks in the "peckerheads" and the two-hole compression lugs we had on hand mated up with the terminal bolts exactly. Landed each set from opposing directions, lapping the flat part of the lugs over the terminal bolts.

 

[bdarnell]

In the only couple of times I have used parallel feeders to a motor, I used Polaris connectors to make the connections. Worked great and no taping !

 

[iwire]

Short answer.

Once you get into equipment sizes that are generally supplied with parallel conductor sets, the equipment will have provisions for as many sets as you need.

As smart $ has mentioned you can specify the terminals you need when ordering the equipment.

For example an 800 amp breaker is likely to ship with terminals that will accept three 600 kcmil conductors per terminal.

 

[rcwilson]

If the parallel feeders are used to compensate for voltage drop or derating in underground conduits, you can set a J-box next to the motor and use an appropriate connector or terminal block to switch to a single conductor, assuming that the single conductor has enough amapcity in the motor's enviroment.

Otherwise, buy the motor with an oversized junction box, you'll need it.